<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <link rel="stylesheet" href="mypic.css">
    <title>我的图片精灵</title>
    <style>
        body{
            margin: 0;
        }
        #box{
           
            width:42.6px;
            height: 41.6px;
            margin: 400px auto;
            border-radius: 10%;
        } 
    </style>
</head>
<body>
    <div id="box" class="twelve"></div>
</body>
</html>